Air pollution is a growing problem in most cities (big and small). The "Daily Dose" aims to disseminate the best available information on air pollution and engage in discussions to better understand the process of air quality management. For more details on the program, please visit http://www.urbanemissions.info

Wednesday, June 01, 2011

Bhutan's Capital, Thimpu, Facing Environmental Challenges

Over the past few decades, Thimphu – the capital of Bhutan – has transformed from a beautiful little town into a modern, concrete city. But urban expansion has come at the cost of severe environmental degradation. Climate change is putting the city at even greater risk. Thimphu is one of 15 cities in the world most vulnerable to the impact of global warming, according to a recent report by the International Institute for Environment and Development, a London-based research organisation.

The city sprawls down steep slopes between altitudes of 2,248 metres and 2,648 metres. Thimphu’s sharp inclines – many with gradients greater than 30% – make the city particularly vulnerable to landslides. Heavy rainfall and sudden cloudbursts, which increase the risk of landsides, will become more frequent as a result of climate change, according to the Intergovernmental Panel on Climate Change (IPCC) 2007 assessment report.Thimphu’s urban development began at a slow pace in 1961, with the launch of Bhutan’s first Five-Year Plan. But it was not until the kingdom opened its doors to the outside world in the 1970s, that the process of urbanisation really started to take hold. Since then, there has been considerable construction in the city centre and suburban development has mushroomed.

According to Bhutan’s National Statistics Bureau, Thimphu had a population of 104,214 in 2010, and is growing at a rate of 1.3% every year. Thimphu will continue to expand in the future, as migration from villages to the city becomes ever more popular.The environmental effects of this urban expansion are visible to anyone who visits the capital. In the past, ecologically rich wetlands were interspersed with the city’s buildings – visible by the swimming pool complex and the Changlimithang Stadium, south of the sewage-treatment plant in Babesa, near the cremation ground by the river and next to the settlement of Langjophaka. Today, most of the wetlands have been converted into residential areas, shopping complexes, sports and recreational spaces. Only a few remain, but they too are at risk of disappearing.

Waste management has always been a problem in Thimphu, but the situation has deteriorated with the expanding population. According to Thimphu City Corporation records, the capital of Bhutan produced about 18,000 tonnes of waste in 2009, which means almost 50,000 kilograms every day. The waste-management system is already struggling to cope, but it is estimated that, by 2020, some 81,000 kilograms of waste will be produced every day.

In 2009, local waste comprised mainly organic materials, as well as some paper and plastic. But now electronic waste – particularly refrigerators, computers and mobile phones – is being dumped out in the open along with other waste, increasing the risk of dangerous chemicals leaking into soil and downstream water supplies.

With more and more Bhutanese settling in Thimphu, the numbers of vehicles are increasing too. Of the 53,382 vehicles in the country, 29,139 are in Thimphu and major cities in the west, according to the Royal Bhutan Police Traffic Division. Higher vehicle numbers have led to a higher demand for road construction in the fragile mountains, and increased traffic on the 11-kilometre Thimphu-Babesa expressway has destroyed many bird habitats. The ongoing river diversion work on the Thimphu River has also resulted in further destruction of bird habitats.

According to the National Environment Commission, Thimphu and the town of Phuentsholing on the border with India have experienced deteriorating air quality over the years. Daily air-pollution levels now often exceed WHO guidelines. Sources of air pollution include combustion of biomass and fossil fuels, industrial emissions, dust from unpaved roads, new construction sites and bitumen heating for road construction.

Houses in Thimphu are poorly designed when it comes to storing heat during the cold winters. Improving building design could save energy and money in the long run. If building designs are improved, energy consumption could be drastically reduced. For example, in an average household, windows account for 15% to 30% of the total heat loss. Well-designed, large glass windows could save energy through the benefits of passive solar heating. While the initial cost of installing double-glazed windows is high, by reducing energy loss by up to 18%, such a move would eventually pay for itself. Advanced insulation materials can reduce the energy consumption of buildings by as much as 90%, according to the architect Herbert Girardet.

Although such solutions are available, they are seldom used, while the capital of this remote country hurtles to catch up with the rest of the world.

Dawa T Wangchuk is a reporter for Business Bhutan, the country's only financial newspaper